Small organelles containing potassium ion channels have been isolated from axoplasm of squid giant axons. These preparations have been fractionated based on size with a control pore size glass bead column. Two classes of vesicles are obtained with this technique: one class consisting of vesicles approximately 150 nm in diameter, and a second containing relatively small vesicles in the 30-50 nm diameter range. The latter preparations contain the motor ATPase, kinesin, and the delayed rectifier potassium ion channel, similar to the delayed rectifier in the axonal membrane based on immunoblots and incorporation of these vesicles in artificial lipid bilayers. These vesicles appear to be involved in the recycling of ion channels in the axonal membrane. The other class of vesicles may well be endocytotic in origin. They also contain potassium ion channel immunoreactivity which differs from that of the smaller vesicles, possibly reflecting changes in the channel due to degradation, or "aging". Both classes of vesicles are distinct from synaptic vesicles which are also found in axoplasm and which are apparently in transit to and from the nerve terminal.